Bluetooth scanning not returning results (On self made app), what can I do?


AC Question

Bluetooth scanning not returning results (On self made app)

I've been having some problems getting Bluetooth to scan for devices with my Samsung Galaxy s5.

I'm on Android 6.0 and have set up permissions for my app to scan like so:

// Android M Permission check
if (this.checkSelfPermission(android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
final AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("This app needs location access");
builder.setMessage("Please grant location access so this app can devices.");
builder.setPositiveButton(android.R.string.ok, null);
builder.setOnDismissListener(new DialogInterface.OnDismissListener() {

public void onDismiss(DialogInterface dialog) {
requestPermissions(new String[]{android.Manifest.permission.ACCESS_COARSE_LOCATION}, PERMISSION_REQUEST_COARSE_LOCATION);

I assume this is working correctly because I got the pop-up asking for permissions which I accepted.

My scan function:

private void scanLeDevice(final boolean enable) {
if (enable) {
// Stops scanning after a pre-defined scan period.
mHandler.postDelayed(new Runnable() {
public void run() {
mScanning = false;
Log.i("start" , "Stopping scan...");

mScanning = true;
Log.i("start" , "Starting scan...");
} else {
mScanning = false;


Now it stops and starts scanning correctly since Logcat is giving me logs. But it's just not finding any devices which is really weird because I'm sitting next to my laptop and a second phone both with Bluetooth enabled.

Here's my callback by the way, if anyone is interested:

Private ScanCallback mScanCallback = new ScanCallback() {

public void onScanResult(int callbackType, ScanResult result) {
System.out.println("BLE// onScanResult");
Log.i("callbackType", String.valueOf(callbackType));
Log.i("result", result.toString());
BluetoothDevice btDevice = result.getDevice();

public void onBatchScanResults(List<ScanResult> results) {
System.out.println("BLE// onBatchScanResults");
for (ScanResult sr : results) {
Log.i("ScanResult - Results", sr.toString());

public void onScanFailed(int errorCode) {
System.out.println("BLE// onScanFailed");
Log.e("Scan Failed", "Error Code: " + errorCode);

Now as you can see the scan is not failing since Logcat is not giving me a scan failed log, but apperantly its also not finding any devices...


06-07 17:13:02.622 16802-16802/com.example.joey.findmycar I/start: Starting scan...
06-07 17:13:02.802 16802-16802/com.example.joey.findmycar W/DisplayListCanvas: DisplayListCanvas is started on unbinded RenderNode (without mOwningView)
06-07 17:13:02.882 16802-16802/com.example.joey.findmycar I/Timeline: Timeline: Activity_idle id: android.os.BinderProxy@c8fddba time:699666571
06-07 17:13:14.632 16802-16802/com.example.joey.findmycar I/start: Stopping scan...
I've added the correct permissions to my Manifest:

<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.BLUETOOTH_PRIVILEGED" />

I've tried almost every possibility and am starting to think the Bluetooth on my phone might be broken somehow, which is weird because I can manually detect and connect to devices in the Android settings.

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